Ron Artest added 15 points for the Lakers, who stared down elimination by jumping to a 22-point lead during a dazzling first half. With remarkable ease, the defending champions stretched the finals to the limit for the first time since 2005.

A champion will be crowned Thursday night at Staples Center - the first winner-take-all game in the NBA finals since San Antonio beat Detroit in 2005.

Ray Allen scored 19 points for the Celtics, who took an ugly pratfall on the verge of winning their unprecedented 18th title. It turns out their longtime rivals are still quite serious about earning their 16th.

The Celtics lost Kendrick Perkins in the first quarter when he went down after grabbing an offensive rebound and getting fouled by Andrew Bynum. Perkins went to the floor and eventually was helped by two teammates to the back, where the team said he would get X-rays.

Izzo sticks with spartans

EAST LANSING, Mich. — Tom Izzo resisted the temptation of possibly coaching LeBron James to focus instead on a sure thing — building the next

generation of superstars at Michigan State.

“Instead of coaching them in the NBA, I’m going to coach them in the NCAA,” Izzo said Tuesday night at a news conference after he turned down a chance to coach the Cleveland Cavaliers.

Izzo rejected the NBA in part because he was unable to speak with James, though he did speak with people in his camp.

“That was one of the key factors, 100 percent true,” Izzo said. “That was not the only factor. Was it a big factor? Sure.”

For the past nine days, Izzo has been trying to decide whether to leave the place that has been his home since 1983 and jump to the NBA to perhaps make

$6 million — doubling his salary — and possibly coach one of the best basketball players in the world.